[SCSI] ibmvfc: Improve LOGO/PRLO ELS handling

There are several scenarios where the ibmvfc driver needs to
try to log back into a target on the fabric. Today when these events
occur, we simply go through re-discovery for all attached targets,
assuming that either the query of the name server or an ADISC will
indicate we might need to log back into the target, which doesn't
work for all scenarios. Fix this by taking note of the affected target(s)
in these conditions and ensuring we try to PLOGI back into the target.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/ibmvscsi/ibmvfc.c

@@ -1484,6 +1484,27 @@ static void ibmvfc_log_error(struct ibmvfc_event *evt)
 		    rsp->flags, rsp_code, scsi_get_resid(cmnd), rsp->scsi_status);
 }
 
+/**
+ * ibmvfc_relogin - Log back into the specified device
+ * @sdev:	scsi device struct
+ *
+ **/
+static void ibmvfc_relogin(struct scsi_device *sdev)
+{
+	struct ibmvfc_host *vhost = shost_priv(sdev->host);
+	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
+	struct ibmvfc_target *tgt;
+
+	list_for_each_entry(tgt, &vhost->targets, queue) {
+		if (rport == tgt->rport) {
+			ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
+			break;
+		}
+	}
+
+	ibmvfc_reinit_host(vhost);
+}
+
 /**
  * ibmvfc_scsi_done - Handle responses from commands
  * @evt:	ibmvfc event to be handled
@@ -1516,7 +1537,7 @@ static void ibmvfc_scsi_done(struct ibmvfc_event *evt)
 			if ((rsp->flags & FCP_SNS_LEN_VALID) && rsp->fcp_sense_len && rsp_len <= 8)
 				memcpy(cmnd->sense_buffer, rsp->data.sense + rsp_len, sense_len);
 			if ((vfc_cmd->status & IBMVFC_VIOS_FAILURE) && (vfc_cmd->error == IBMVFC_PLOGI_REQUIRED))
-				ibmvfc_reinit_host(evt->vhost);
+				ibmvfc_relogin(cmnd->device);
 
 			if (!cmnd->result && (!scsi_get_resid(cmnd) || (rsp->flags & FCP_RESID_OVER)))
 				cmnd->result = (DID_ERROR << 16);
@@ -2181,6 +2202,7 @@ static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
 				struct ibmvfc_host *vhost)
 {
 	const char *desc = ibmvfc_get_ae_desc(crq->event);
+	struct ibmvfc_target *tgt;
 
 	ibmvfc_log(vhost, 3, "%s event received. scsi_id: %llx, wwpn: %llx,"
 		   " node_name: %llx\n", desc, crq->scsi_id, crq->wwpn, crq->node_name);
@@ -2218,9 +2240,23 @@ static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
 	case IBMVFC_AE_SCN_NPORT:
 	case IBMVFC_AE_SCN_GROUP:
 		vhost->events_to_log |= IBMVFC_AE_RSCN;
+		ibmvfc_reinit_host(vhost);
+		break;
 	case IBMVFC_AE_ELS_LOGO:
 	case IBMVFC_AE_ELS_PRLO:
 	case IBMVFC_AE_ELS_PLOGI:
+		list_for_each_entry(tgt, &vhost->targets, queue) {
+			if (!crq->scsi_id && !crq->wwpn && !crq->node_name)
+				break;
+			if (crq->scsi_id && tgt->scsi_id != crq->scsi_id)
+				continue;
+			if (crq->wwpn && tgt->ids.port_name != crq->wwpn)
+				continue;
+			if (crq->node_name && tgt->ids.node_name != crq->node_name)
+				continue;
+			ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
+		}
+
 		ibmvfc_reinit_host(vhost);
 		break;
 	case IBMVFC_AE_LINK_DOWN: